Ester hydrolysis

ABSTRACT

A catalyst composition comprising a perfluorinated ion-exchange polymer containing sulfonic acid groups supported on an inert carrier having a hydrophobic surface with a mean pore diameter of at least 1000 Å. Use of this catalyst provides improved hydrocarbon conversion processes for oligomerization of olefins, hydration of olefins and hydrolysis of esters.

This is a division of application Ser. No. 07/788,389, filed Nov. 6,1991, now U.S. Pat. No. 5,233,102 which in turn is a division ofapplication Ser. No. 07/388,400 filed Aug. 2, 1989, now U.S. Pat. No.5,094,995.

FIELD OF THE INVENTION

This invention relates to supported perfluorinated ion-exchangepolymers, and to the use of the supported polymers in acid-catalyzedreactions.

BACKGROUND OF THE INVENTION

Perfluorinated ion exchange polymers with pendant sulfonic acid groupshave been used in a wide variety of acid catalyzed reactions, includinghydrocarbon conversion reactions such as acylation, carbonylation,condensation, alkylation and oligomerization. For a review, see Walleret al., Chemtech, July, 1987, pp 438-441, and references therein.

In these acid catalyzed reactions, the perfluorinated ion exchangepolymers with sulfonic acid groups have been used in the form ofpowders, films, cubes, flakes and tubes. In general, the catalyticefficiency (amount of product divided by the amount of catalyst) of suchpolymers is related to surface area, so that the powders of polymersshow higher activity than cubes in non-swelling solvents. However, fineparticulate particles tend to exhibit poor flow dynamics and lead toplugging problems and loss of catalyst due to entrainment. Films andflakes are inconvenient forms to use in many large scale industrialprocesses. Perfluorinated ion exchange polymers containing sulfonic acidgroups in the form of tubing have only a moderate surface area to weightratio and are fragile and difficult to manufacture.

Perfluorinated ion exchange polymers with pendant sulfonic acid groupshave also been coated on various supports to increase the number of acidsites available, providing catalysts with increased catalytic efficiencyat a lower cost.

U.S. Pat. No. 4,661,411 discloses the preparation of a heterogeneousacid catalyst, which involves treating a carrier material with asolution, which contains a fluorinated polymer dissolved in a suitablesolvent, such polymer having sulfonic acid functional groups; removingthe solvent involved in the prior step; and heat treating or annealingthe coated carrier in a fashion to prevent the polymer from beingleached from the carrier. Aqueous ethanol, particularly 50% aqueousethanol used at 250° C. or higher for several hours in an autoclave, isa suitable solvent for dissolving the unannealed fluorinated polymer.The composition of the carrier is not considered critical, and several,including carbon are suggested.

U.S. Pat. No. 4,038,213 discloses the preparation of a supportedperfluorinated polymer catalyst by dissolving the polymer (aperfluorinated ion exchange polymer containing pendent sulfonic acidgroups) in a solvent, such as ethanol, mixing the support and thecatalyst solution, and then drying the impregnated support under vacuum.Disclosed supports or carriers have an average pore diameter of 50 to600 Å and are inorganic oxides such as alumina, fluorided alumina,zirconia, silica, silica-alumina, magnesia, chromia, boria, and mixturesthereof; other suitable porous supports include bauxite, kieselguhr,kaolin, bentonite, diatomaceous earth, polytetrafluoroethylene, carbon(e.g., charcoal), polytrichlorofluoroethylene and porous glass. Thesupported catalyst is useful in hydrocarbon conversion reactions, e.g.,alkylation of isoparaffins, isomerization of normal alkanes,disproportionation of toluene and the alkylation of benzene.

U.S. Pat. No. 4,303,551 discloses an improved process for makingsupported perfluorosulfonic acid catalyst, comprising converting thesulfonic acid groups to the quaternary ammonium or phosphonium salts toeffect solubility of the polymers, depositing the polymer containing thequaternary ammonium or phosphonium salts on a support, then, convertingthe ammonium or phosphonium salts to the sulfonic acid. The ammonium orphosphonium salts are soluble in dipolar, aprotic solvents such asdimethylformamide and dimethyl sulfoxide. A process is also disclosedfor preparing a supported perfluorocarbon polymer containing pendantacid groups by first coating the support with a thin film of a catalystprecursor containing pendant groups which are convertible to acidgroups, and then converting only the surface layer of said pendantgroups into acid groups. Suggested supports include metal, Teflon®fibers, asbestos, glass, ceramics, sulfonyl fluoride polymers, and theperfluorocarbon sulfonyl fluoride itself.

In general, the supports have been chosen for their low cost, highsurface area, inertness under the reaction conditions, mechanicalstrength or a combination of these factors. Little consideration hasbeen given to the effect of the hydrophilic/hydrophobic nature of thesupport surface on the catalytic activity of the supported catalyst.

Quite unexpectedly, it has been found that catalysts obtained by coatingperfluorinated ion exchange polymers with pendant sulfonic acid groupson supports with hydrophobic surfaces are significantly more active inacid-catalyzed reactions than similar catalysts prepared from supportswith hydrophilic surfaces.

SUMMARY OF THE INVENTION

This invention provides improved hydrocarbon conversion processes whichcomprise contacting said hydrocarbons under hydrocarbon convertingconditions with a catalyst composition comprising 0.05-3.0% by weight ofa perfluorinated ion exchange polymer containing sulfonic acid groupssupported on an inert carrier, wherein the surface of the carrier ishydrophobic and has a mean pore diameter of at least 1000 Å. Theimproved processes include oligomerization of olefins, hydration ofolefins and hydrolysis of esters.

This invention also provides a novel catalyst composition comprising aperfluorinated ion-exchange polymer containing sulfonic acid groupssupported on an inert carrier having a hydrophobic surface with a meanpore diameter of at least 1000 Å. In particular the carrier comprisescalcined shot coke.

DETAILED DESCRIPTION OF THE INVENTION

The catalysts which are used in the processes of this invention areprepared by contacting the hydrophobic support with a solution of thesulfonic acid substituted perfluorinated ion exchange polymer, removingthe excess solvent to give a coated support, and activating the coatedsupport by treatment with a strong mineral acid to give the supportedcatalyst.

The polymers that are suitable for use in this invention have structuresthat include a substantially fluorinated carbon chain that may haveattached to it side chains that are also substantially fluorinated, andcontain sulfonic acid groups or derivatives of sulfonic acid groups.Such polymers for use in this invention have an equivalent weight of atleast about 500. Preferably, the perfluorinated polymer contains asufficient number of sulfonic acid groups to give an equivalent weightof from about 500 to about 20,000, and most preferably from about 900 toabout 2,000. Although the polymer backbone comprises, for the most part,fluorinated carbon atoms, it is not necessary that all other atoms beexcluded. For example, ether oxygen atoms may be present in thebackbone, as well as in the side chains of the polymer. Such other atomsand/or groups as hydrogen (H), chlorine (Cl) and carboxy (COOH) may bepresent in limited amounts without significantly affecting the stabilityor operability of the polymer under process conditions. It is preferredthat the polymer contain no greater than about 5 weight percent total ofhydrogen and chlorine groups. Representative of the perfluorinatedpolymers suitable for use in the present invention are the Nafion®polymers (a family of catalysts for use in the manufacture of industrialchemicals, commercially available from E. I. du Pont de Nemours andCompany), and the polymers, or derivatives of polymers, disclosed inU.S. Pat. Nos. 3,282,875; 4,329,435; 4,330,654; 4,358,545; 4,417,969 and4,610,762, which are hereby incorporated by reference.

Typically, suitable perfluorinated polymers are derived fromsulfonylhalide group-containing polymers having a fluorinatedhydrocarbon backbone chain to which are attached the functional groupsor pendant side chains which in turn carry the functional groups. Thependant side chains can contain, for example, ##STR1## groups, whereinR_(f) is F, Cl, or a C₁ to C₁₀ perfluoroalkyl radical. Ordinarily, thefunctional group in the side chains of the polymer will be present interminal ##STR2## positions.

Although the fluorinated portion of the polymer molecule is in largepart responsible for the desirable thermal stability of these polymers,it also contributes to the low solubility, and hence difficultprocessability, of these materials. However, it is possible to dissolvethe polymer by heating it with an aqueous alcohol, particularly 50%aqueous ethanol, to about 250° C. or higher for several hours in a highpressure autoclave (Martin et al., Anal. Chem., Vol. 54, pp 1639-1641(1982). Other solvents and mixtures may also be effective in dissolvingthe polymer. See, for example, U.S. Pat. No. 4,433,082.

Ordinarily, for each part by weight of polymer employed to be dissolved,from as little as about 4 or 5 parts by weight up to about 100 parts byweight, preferably 20-50 parts by weight, of the solvent mixture areemployed. In the preparation of the dissolved polymer, there is aninteraction between the equivalent weight of the polymer employed, thetemperature of the process, and the amount and nature of the solventmixture employed. For higher equivalent weight polymers, the temperatureemployed is ordinarily higher and the amount of liquid mixture employedis usually greater.

The resulting mixture may be used directly, but it is preferred that themixture be filtered through fine filters (e.g., 4-5.5 micrometers) toobtain clear, though perhaps slightly colored, solutions. The mixturesobtained by this process can be further modified by removing a portionof the water, alcohols and volatile organic by-products by distillation.

Commercially available solutions of perfluorinated ion-exchange polymerscan also be used in the preparation of the supported polymer catalystsof the present invention (e.g., a 5 wt. % solution of a perfluorinatedion-exchange powder in a mixture of lower aliphatic alcohols and 10%water, Cat. No. 27,470-4, Aldrich Chemical Company, Inc., 940 West SaintPaul Avenue, Milwaukee, Wis. 53233).

The polymer can be deposited on the support by soaking the support inthe liquid mixture containing the polymer and then removing any excesssolvent. Typically, the coated support is dried at a temperature abovethe boiling point of the solvents for at least 1 hour. Alternatively,the supported polymer can be prepared by atomizing the coating solutionin air in a sonic velocity nozzle as in U.S. Pat. No. 4,430,001, hereinincorporated by reference. Preferably, the supported polymer is preparedusing a fluidized bed as detailed in the examples.

The thickness of the coating can be varied by adjusting theconcentration of the polymer in the liquid mixture or by applying two ormore layers of polymer onto the support. Suitable weight ratios ofpolymer-to-support vary from about 0.05 to about 3.0%. Higher weightratios are possible, but less economic.

The composition of the support has been found to be important, howeverthe properties that are considered most desirable for a carrier may varyin different applications. Properties that may be important in somesituations include high surface area, high crush strength, highporosity, chemical resistance, thermal stability, and low cost. In allcases, the support must be resistant to the liquid composition of thepolymer blend and to the temperatures used during the drying of thecatalyst. For the catalysts used in the processes of this invention, itis also important that the surface of the support be hydrophobic.Preferred supports with hydrophobic surfaces includepolytetrafluoroethylene, copolymers of polytetrafluoroethylene andhexafluoropropylene, polyethylene, polypropylene and carbon in the formof coke.

A specifically preferred support is coke. "Coke" as used herein is thenon-volatile residue of petroleum refining or coal distillationoperations. Its composition depends on the source of the feedstock andthe processing methods used. In general, it has a high C:H ratio andcontains condensed, polynuclear aromatic compounds as well as organicand inorganic compounds of sulfur, nitrogen and metals such as vanadium,nickel, iron and copper. Coke includes a very broad range of hydrophobicmaterials including tar pitch coke, coke oven coke, needle coke, regulargrade or anode coke, fuel grade coke, shot coke, speciality carbon cokessuch as gilsonite coke or others. Although the coke may be used in thegreen uncalcined form, it is preferable that the coke be calcined.

The most preferred support is calcined shot coke. Calcined shot cokealone is not a catalyst for hydrocarbon conversion reactions. The poresize range for conventional catalyst support material is between 50 and600 Å. In contrast, the mean pore diameter in calcined shot coke is inexcess of 1000 Å, and the average surface area is 0.1-10.0 m² /g. It isunusual that a material with such large pores provides an effectivesupport medium for catalysis. Calcined shot coke also has a very highcrush strength. The preferred loading for calcined shot coke is0.05-3.0%; higher loadings are possible, but are less cost-efficient.Even coatings less than a monolayer thick of the polymer on the calcinedshot coke result in a catalyst of high activity.

The supported perfluorinated ion-exchange polymers described herein canbe used for hydrocarbon conversion reactions in continuous processes orin batch reactions.

Catalytic activity of the supported catalysts gradually decreases withuse, but can be substantially restored by treatment with dilute acid,preferably 1N nitric acid, at about 80° C. In general, the integrity ofthe coated catalyst is maintained through many reaction cycles. Thecoating does not dissolve or flake off under the conditions of thehydrocarbon conversion reactions.

The oligomerization of olefins is one of many industrially importantacid-catalyzed reactions. Known catalysts for the process include bothhomogeneous and heterogeneous, organic and inorganic, acids. Generally,heterogeneous catalysts are preferred because of the ease of theirseparation from the reaction mixtures.

The oligomerization of olefins involves the condensation of olefins tocompounds of higher molecular weight. The distribution of oligomersbetween dimers, trimers, tetramers and higher molecular weight productsdepends both on the reaction conditions and the olefin startingmaterial. Generally those olefins which can form relatively stablecarbonium ions upon protonation oligomerize most easily. Rearrangementsof the condensed products also occur frequently, especially for highlysubstituted olefins. The oligomerization of olefins is useful for theconversion of low molecular weight, often gaseous, hydrocarbons tohigher molecular weight liquid or solid products. In particular, lowmolecular weight materials can be converted to blending components forgasoline.

In one process of this invention, the oligomerization of olefins iscarried out by contacting at about 135° C. to 185° C. an olefin chosenfrom the group of monoolefins containing 3 or more carbons with acatalyst composition comprising 0.05-2.0 weight percent of aperfluorinated ion exchange polymer containing sulfonic acid groupssupported on the surface of an inert support having a hydrophobicsurface with a mean pore diameter of about 1000 Å. Preferably, the inertsupport is calcined shot coke.

In another process of this invention, the hydrolysis of esters iscarried out by contacting in the presence of water and at a temperatureof from about 75° C. to about 225° C., an ester chosen from the groupconsisting of esters of C₃ to C₈ dicarboxylic acids with a catalystcomposition comprising 0.05-2.0 weight percent of a perfluorinated ionexchange polymer containing sulfonic acid groups supported on thesurface of an inert support having a hydrophobic surface with a meanpore diameter of about 1000 Å. Preferably, the temperature is from about130° C. to about 180° C. and the ester is chosen from the groupconsisting of mono- or dimethyl adipate or mono- or dimethyl glutarate.Most preferably, the inert support is calcined shot coke and the esteris dimethyl adipate.

The hydration of olefins to convert hydrocarbons to alcoholsindustrially important reaction that is often difficult to catalyze. Inanother process of this invention, the hydration of olefins is carriedout by contacting in the presence of water and at a temperature of about180° C. to about 250° C., an olefin chosen from the group of monoolefinscontaining 2 or more carbon atoms and a catalyst composition comprising0.05-2.5 weight percent of a perfluorinated ion exchange polymercontaining sulfonic acid groups supported on an inert support having ahydrophobic surface with a mean pore diameter of about 1000 Å.Preferably, the olefin is chosen from the group of C₂ to C₂₀monoolefins, the temperature is about 200° C. to about 240° C. and theolefin is in the gas phase. Most preferably, the olefin is ethylene,propylene, isobutylene or 1-butene and the inert support is calcinedshot coke.

EXAMPLES

The following Examples are presented for the purpose of illustration andare not in any way to be construed as limiting the scope of theinvention as described herein.

EXAMPLE 1

Example 1 illustrates the preparation of a perfluorinated ion exchangepolymer containing sulfonic acid groups on a calcined shot coke support.A liquid composition of such a perfluorinated polymer (100 mL of a 5weight percent solution of polymer having an equivalent weight of 1100in a mixture of lower aliphatic alcohols and 10% water, Aldrich Chem.Co., Cat. No. 27,470-4) was added to calcined shot coke (400 g, 10-20mesh, 0.42 m² /g). The coated catalyst was rotated occasionally for 0.5hour and then the small amount of non-adsorbed solution was decantedoff. The coated coke was dried at 80° C. for 1.5 h in vacuo. Thiscoating procedure was repeated with another 100 mL of the liquidcomposition of the polymer, which was completely adsorbed. The coatedcoke was thoroughly dried in a vacuum oven for 12 hours at 110° C. Theresulting coated shot coke weighed 407 g. The dried, coated coke wastreated with dilute HNO₃ (approx. 1M, 860 mL) for 1 hour at 80° C. toconvert the functional groups to sulfonic or carboxylic acid groups. Theactivated catalyst was washed with 300 mL of distilled water and driedin a vacuum oven at 110° C. for 3 hours.

The dried and activated catalyst was titrated with NaOH by adding a 1.59g portion of the catalyst to 20 mL of water containing 1.0 g of NaCl and3 drops of 1% phenolphthalein in methanol. The pink color of theindicator persisted for 5 minutes after 2.85 mL of 10⁻² N NaOH wasadded, implying that the ion-exchange capacity (hereinafter IEC) is17.92×10⁻³ mequiv/g. Similarly, the IEC of the uncoated CSC wasdetermined to be 0.24×10⁻³ mequiv/g. This implies a corrected IEC forthe coated support of 17.68×10⁻³ mequiv/g, corresponding to a 1.94%loading (based on IEC=0.909 mequiv/g of the polymer).

EXAMPLES 2-3

Examples 2 and 3 were prepared as described for Example 1, using thereagent quantities summarized in Table 1.

                                      TABLE 1                                     __________________________________________________________________________    Preparation of Catalyst                                                                               Corrected                                             Example                                                                             Calcined                                                                             Polymer    IEC      Loading                                      Number                                                                              Shot Coke                                                                            Solution   mequiv/g × 10.sup.3                                                              %                                            __________________________________________________________________________    1     400 g  2 × 100 mL                                                                         17.68    1.94                                               10-20 mesh                                                                           (5 wt. %)                                                        2     174 g  40 mL (5 wt. %) +                                                                        4.58     0.57                                               >10 mesh                                                                             20 mL MeOH                                                       3     159 g  [40 ml (5 wt. %) +                                                                       8.33     0.92                                               >10 mesh                                                                             20 mL MeOH]                                                                   +                                                                             [40 mL (5 wt. %) +                                                            20 mL MeOH]                                                      __________________________________________________________________________

EXAMPLES 4-6

Examples 4-6 illustrate the oligomerization of isobutylene. A quartzequivalent of a Fisher-Porter tube was charged with isobutylene (15.0g), toluene (15 mL), chlorobenzene (1.0 g, internal standard) andcatalyst from Examples 1-3 respectively, and heated to 110° C. for 35min. The products were analyzed by gas chromatography using a flamedetector, a 0.31 mm (i.d.)×25 m column packed with cross-linked methylsilicone, and He gas at 20 mL/min. The temperature was held at 40° C.for 2 min, increased to 180° C. at a rate of 16° C./min, and held at180° C. for 5 min.

The results of the oligomerization reactions are summarized in Table 2for the catalysts of Examples 1-3 and comparative catalysts A-E.

                  TABLE 2                                                         ______________________________________                                        Oligomerization of Isobutylene                                                Catalyst                       Pro-                                           Example     Loading  IEC/lb..sup.d ×                                                                   duc-  Activity.sup.b ×                   Number      %        10.sup.-3 tivity.sup.a                                                                        10.sup.-3                                ______________________________________                                        Example                                                                       4   Ex. 1       1.94     8.03    1401  174                                    5   Ex. 2       0.57     2.08    341   164                                    6   Ex. 3       0.92     3.78    599   158                                    Comparative Examples                                                          A   Amberlyst 15                                                                              --       2130    1510  0.71                                   B   PFIEP-SO.sub.3 H.sup.e                                                                    --       360     669   1.86                                       10-35 mesh                                                                C   Calcined    --       --      N.R.  --                                         shot coke                                                                     (10-20 mesh)                                                              D   XU-40036.01.sup.c                                                                         14       63.6    1252  19.69                                  E   XU-40035.01.sup.c                                                                         22       99.9    900   9.01                                   ______________________________________                                         .sup.a Productivity = (Moles of C4 reacted) (lb. catalyst).sup.-1             (hour).sup.-1                                                                 .sup.b Activity = (Moles of C4 reacted) (IEC).sup.-1                          .sup.c XU40036.01 and XU40036.02 are examples of fluorocarbonsulfonic aci     polymers on alumina and silicon carbide, respectively (Dow Chemical Co.)      .sup.d IEC is in "equivalents" .                                              .sup.e PFIEPSO.sub.3 H is perfluorinated ionexchange polymer containing       sulfonic acid groups.                                                    

EXAMPLES 7-13

Examples 7-13 illustrate the hydrolysis of dimethyl adipate. The initialcharge of 100 mL H₂ O, 12 g dimethyl adipate (DMA) and 20 g catalyst(0.5% Nafion® on calcined shot coke prepared as in Example 1) was heatedin an autoclave reactor to 160° C. or 180° C. A small agitator wasrotated at 300 rpm. A total of 100 mL H₂ O was pumped into the autoclaveduring 1 or 2 hours reaction period while venting out water and methanolat the same rate as water was pumped in. After the end of the reactionperiod (1-4 hours), the contents of the autoclave were cooled to about90° C. and the catalyst separated by filtration for use in furtherexperiments. The major products were adipic acid (AA) and mono-methyladipate (MMA).

                  TABLE 3                                                         ______________________________________                                        Hydrolysis of Dimethyl Adipate                                                                                Product Composition                                                 H.sub.2 O pumped in                                                                     (Water Free Basis),                                Temp.   Reaction (= vented out)                                                                          % by weight                                   Ex.  °C.                                                                            Time, h  (mL)      DMA   MMA   AA                                ______________________________________                                         7   160     2        205       0.74  11.6  86.8                               8   160     4        200       0.14  0.22  99.1                               9   160     2        200       0.36  11.6  87.2                              10   160     1        200       0.99  31.3  66.0                              11   160     1        200       1.22  3.6   93.9                              12   180     2        200       0.18  0.39  99.1                              13   180     2        100       0.45  0.82  98.4                              ______________________________________                                    

EXAMPLES 14-16 AND COMPARATIVE EXAMPLE F

These examples illustrate the hydration of ethylene and propylene. Asynthetic gas mixture of ethylene (7.5%), propylene (3.0%) and thebalance hydrogen and methane was heated to 220° C. or 235° C., bubbledthrough water to attain a humidity level of about 75% of saturation atthe give temperature and then fed into a Cat Poly Lab Reactor whichcontained Nafion® (Comparative Example F) or calcined shot coke coatedwith Nafion® prepared as in Example 1 (2.5-2.9 weight percent). Themajor products were ethanol and isopropanol. In this example, use ofsupported Nafion® is much less costly than use of Nafion® and istherefore advantageous.

                  TABLE 4                                                         ______________________________________                                        Hydration of Ethylene and Propylene                                                 Catalyst Temp.    % Conversion                                          Ex.   Loading  (°C.)                                                                           C2 to Ethanol                                                                           C3 to Isopropanol                           ______________________________________                                        14    2.5%     220      3.5       4.7                                         15    2.9%     220       3.9*      2.9*                                       16    2.5%     235      5.7       4.0                                         F     --       235      5.8       4.7                                         ______________________________________                                         *Run interrupted by power failures, and aborted prematurely. Conversion       data are only estimates.                                                 

EXAMPLE 17

A liquid composition of perfluorinated ion exchange polymer containingsulfonic acid groups as used in Example 1 (4500 g of 11.8% solution ofpolymer of 1100 equivalent weight) in a mixture of lower aliphaticalcohols and 40% water, was sprayed onto a fluidized air-suspended bedof calcined shot coke (15 kg, 35-60 mesh) at 25° C. The material wasdried by the air flow within the fluidized bed until the moisturecontent was <0.1%. The final weight of the coated shot coke was 15.4 kg.The resulting coated coke was treated with dilute HNO₃ (approximately2.4M) for 1 h at 85° C. to convert the functional groups to sulfonicacid groups. The activated catalyst was washed with distilled water anddried in a vacuum oven at 110° C. for 3 h.

The dried and activated catalyst was titrated with NaOH by adding a 1.50g portion of the catalyst to 20 mL of water containing 1.0 g of NaCl and5 drops of bromothymol blue indicator in methanol. The blue color of theindicator persisted for 10 min after 3.68 mL of 0.01N NaOH was added,implying that the ion-exchange capacity (IEC) was 24.53×10⁻³ mequiv/g.The corrected IEC for the coated support was 24.29×10⁻³, correspondingto a loading of 2.67%.

EXAMPLE 18

The composition of materials and the method used were the same as thatin Example 17, except that the temperature of the fluidized bed was keptat 60° C. The final weight of the coated shot coke was 15.3 kg. Aftertreatment with dilute HNO₃, washing and drying, the catalyst wastitrated with 2.76 mL of NaOH as in Example 17. The IEC was 18.40×10⁻³mequiv/g, corrected to 18.16 mequiv/g at a loading of 2.02%.

EXAMPLE 19

The oligomerization of isobutylene was carried out as in Examples 4-6using the supported catalyst of Examples 17 and 18. The results obtainedare summarized in Table 5.

                  TABLE 5                                                         ______________________________________                                        Oligomerization of Isobutylene                                                Catalyst                                                                      Example Loading  IEC/lb.sup.a ×                                                                    Productivity.sup.b ×                         Number  wt. %    10.sup.-3 10.sup.-3 Activity.sup.c                           ______________________________________                                        17      2.67     11.01     1266      115                                      18      2.02      8.34      700       84                                      ______________________________________                                         .sup.a IEC is in "equivalents"                                                .sup.b Productivity = (moles of C.sub.4 reacted) (lb catalyst).sup.-1         (hour).sup.-1                                                                 .sup.c Activity = (moles of C.sub.4 reacted) (IEC).sup.-1 (hour).sup.-1  

What is claimed is:
 1. An improved process for the hydrolysis of esterswherein the improvement comprises contacting said esters with acatalytic composition comprising a perfluorinated ion-exchange polymercontaining sulfonic acid groups supported on an inert carrier whereinsaid carrier comprises calcined shot coke and has a hydrophobic surfacewith a mean pore diameter of at least 1000 Å; at a temperature of fromabout 130° C. to about 180° C.
 2. The process of claim 1 wherein theester is selected from the group monomethyl adipate, dimethyl adipate,monomethyl gluterate of dimethyl gluterate.
 3. The process of claim 2wherein the ester is dimethyl adipate.